Respiratory syncytial virus (RSV), the flu, and the common cold affect the respiratory system, but different viruses cause them and can vary in severity. Knowing how to tell them apart helps you respond appropriately, prevent the spread, and decide when to seek medical attention. While all three share similar symptoms, their onset, intensity, and possible complications set them apart. For same-day illness testing and treatment, visit the walk-in clinic at AFC Urgent Care South Plainfield ...